Justification:
Previously this species had been regarded as Lower Risk/conservation dependent due to its restricted distribution and narrow ecological niche and the fact that it was largely confined to protected areas. Field work over the last decade has indicated that this species should now be regarded as Endangered on the basis of a decline in the quality of habitat due to an increased frequency of fires and die back in some subpopulations.

This species is only known from the highest parts of four mountains in the southern massif - Mt Humboldt , Mt Kouakoué, Montagne des Sources and Mont Mou. A potential fifth area (Mamie) at much lower elevation has not been confirmed. Occurs from 750 to 1,600 m.

Subpopulations on the summits and ridges of Mt Humboldt, Mt Kouakoué and Montagne des Sources are quite extensive although there has been significant die back over the last decade at Mt Humboldt. The subpopulation at Mt Mou is much smaller and more degraded. At Mamie, in an area that represents an atypical habitat at an altitude of 400-500 m asl, a relatively extensive and healthy subpopulation has recently been tentatively identified as A. humboldtensis.

Recent die back may have caused the death of at least 10% of the Mt Humboldt subpopulation. The cause is unknown but may relate to drought induced stress or perhaps an unknown pathogen. Wildfires are currently the main threat. As subpopulations are restricted to a narrow altitudinal range with little possibility for upward expansion, this species may be very susceptible to some of the potential impacts of climate change.

The main subpopulations are within protected areas such as Montagne des Sources and Mont Humboldt although it should be noted that some reserves are open to mining. Fire prevention measures are in place with fire brigades and water-bombing helicopters available if needed.

Jaffré, T., Munzinger, J. and Lowry, P.P. 2010. Threats to the conifer species found on New Caledonia's ultramafic massifs and proposals for urgently needed measures to improve their protection. Biodiversity and Conservation 19: 1485-1502: DOI 10.1007/s10531-010-9780-6.